Cycles option to turn off texture tiling?
Cycles node system is very flexible and allows you to manipulate the UVs in pretty much any way you like. 

The UV channel can be used as if it were just an image where U and V correspond to red and green channels.
These can be separated and manipulated using math nodes to create a mask you can use to clip the texture. 
Here's a screenshot of a node setup doing that: 



This uses the clip mask group to mix the texture to black. You could also use it in a mix material node to mix with a transparent shader or the like.

While making such node groups is a relatively long process, you can append or link the node group whenever necessary after you've made it once.